A boy riding on his bike is going towards east at a speed of m s^-1. At a certain point he produces a sound pulse of frequency 1650 Hz that travels in air at a speed of 334 m s^-1. A second boy stands on the ground 45^o south of east from him. Find the frequency of the pulse as received by the second boy.

Two submarines are approaching each other in a calm sea. The first submarine travels at a speed of 36 km h^-1 and the other at 54 km h relative to the water. The first submarine sends a sound signal (sound waves in water are also called sonar) at a frequency of 2000 Hz. (a) At what frequency is this signal received by the second submarine? (b) The signal is reflected from the second submarine. At what frequency is this signal received by the first submarine. Take the speed of the sound wave in water to be 1500 m s^-1.

A small source of sound oscillates in simple harmonic motion with an amplitude of 17 cm. A detector is placed along the line of motion of the source. The source emits a sound of frequency 800 Hz which travels at a speed of 340 m s^-1. If the width of the frequency band detected by the detector is 8 Hz, find the time period of the source.

A sound source, fixed at the origin, is continuously emitting sound at a frequency of 660 Hz. The sound travels in air at a speed of 330 m s^-1. A listener is moving along the line x=336 m at a constant speed of 26 m s^-1. Find the frequency of the sound as observed by the listener when he is (a) at y = — 140 m, (b) at y = 0 and (c) at y = 140 m.

A train running at 108 km h^-1 towards east whittles at a dominant frequency of 500 Hz. Speed of sound in air is 340 m/s, What frequency will a passenger sitting near the open window hear 7 (b) What frequency will a person standing near the track hear whom the train has just passed? (c) A wind start blowing towards east at a speed of 36 km h^-1. Calculate the frequencies heard by the passenger in the train and by the person standing near the track.